Daunomycin is an antibiotic of the anthracycline series and is a very potent agent against various tumors, and especially against leukemias. The antimetabolic activity of daunomycin corresponds to a certain extent to its ability to penetrate the cell nucleus and intercalate with DNA both via hydrophobic bonds and by the binding of the amino group of the drug to phosphate residues of the nucleic acid. The drug has certain side-effects which hamper its use in clinical practice. The drug has a pronounced toxic effect when used in large dosages: amongst side-effects that may be mentioned: bonemarrow depression, stomatitis, alopecia and cardiac toxicity.